Over-expression of NCS-1 in AtT-20 cells affects ACTH secretion and storage

The effect of over-expressing neuronal calcium sensor 1 (NCS-1) upon stimulated adrenocorticotrophin (ACTH) secretion was studied in AtT-20 cells. Stably-transfected AtT-20 cell lines over-expressing NCS-1 were obtained and compared to wild type AtT-20 cells. Corticotrophin releasing factor (CRF-41)-stimulated ACTH secretion from NCS-1 over-expressing cells was significantly reduced from that obtained in wild type AtT-20 cells. The effects of other stimulants of ACTH secretion from wild type AtT-20 cells were not attenuated in NCS-1 over-expressing cells. Calcium, guanosine 5'-O-(3'-thiotriphosphate) (GTP-gamma-S) and mastoparan stimulated ACTH secretion from permeabilised wild type AtT-20 and NCS-1 over-expressing AtT-20 cells with significantly greater ACTH secretion obtained in NCS-1 over-expressing cells. This study shows that in intact cells over-expression of NCS-1 reduces exocytotic ACTH release, while in permeabilised cells increases ACTH release. NCS-1 has multiple cellular targets and that directly and indirectly via these targets acts to increase the releasable ACTH pool while inhibiting CRF-41 stimulus-secretion coupling.

Relevance of the number of positive bottles in determining clinical significance of coagulase-negative staphylococci in blood cultures

Coagulase-negative staphylococci (CNS) are the most commonly isolated contaminants from blood cultures, yet they frequently cause true infections. Determining the clinical significance of CNS is difficult, and clinicians often consider the number of positive bottles within a set of blood culture bottles in their assessment. Therefore, in three separate studies, we counted the number of positive bottles within blood culture sets comprising two, three, or four bottles in order to predict whether or not CNS were clinically significant isolates (CSI) in adult patients with suspected sepsis. Each culture was evaluated by independent, published clinical criteria to determine its clinical importance. Of 486 positive sets that included two adequately filled bottles, 127 (26%) CNS were CSI, 329 (67%) were contaminants, and 30 (6%) were indeterminate as a cause of sepsis. Among CSI, 39 and 61% were isolated from one and two bottles, respectively. The positive predictive value for sepsis was 18% when one bottle was positive and 37% when both bottles were positive. Of 235 positive sets that included three adequately filled bottles, 81 (34%) were CSI, 109 (46%) were contaminants, and 45 (19%) were indeterminate as a cause of sepsis. Of CSI, 43, 38, and 19% were found in one, two, and three bottles, respectively. The positive predictive value for sepsis was 28, 52, and 30% when one, two and three bottles were positive. Of 303 positive blood culture sets that included four adequately filled bottles, 64 (21%) were considered CSI, 197 (65%) were contaminants, and 42 (14%) were indeterminate as a cause of sepsis. Of CSI, 27, 28, 19, and 27% were found in one, two, three, and four bottles, respectively. The positive predictive value for sepsis was 11, 30, 34, and 37% when one, two, three, and four bottles were positive. We conclude that the number of culture bottles positive in a given culture set cannot reliably predict the clinical significance of the CNS isolated and, therefore, should not be used as a criterion for determining whether or not an isolate represents true infection or contamination.

The effect of changes in laboratory practices on the rate of false-positive cultures for Mycobacterium tuberculosis

CONTEXT

False-positive cultures for Mycobacterium tuberculosis have been found in nearly all DNA fingerprinting studies, but the effectiveness of interventions to reduce cross-contamination has not been evaluated.

OBJECTIVE

To evaluate whether changes in laboratory policies and procedures reduced the rate of false-positive cultures.

DESIGN

Retrospective study of isolates with matching DNA fingerprints.

SETTING

A mycobacteriology laboratory serving an urban tuberculosis control program and public hospital system.

PATIENTS

All M tuberculosis isolates processed from July 1994 to December 1999.

METHODS

Isolates were fingerprinted using IS6110; pTBN12 was used to fingerprint isolates having fewer than 6 copies of IS6110. We further evaluated all patients having only one positive culture whose DNA fingerprint matched that of another isolate processed in the laboratory within 42 days.

INTERVENTIONS

We changed laboratory policy to reduce the number of smear-positive specimens processed and changed laboratory procedures to minimize the risk of cross-contamination during batch processing.

MAIN OUTCOME MEASURE

The rate of false-positive cultures.

RESULTS

Of 13 940 specimens processed during the study period, 630 (4.5%) from 184 patients and 48 laboratory proficiency specimens grew M tuberculosis. There were no cases (0/184) of probable or definite cross-contamination, compared with the 4% rate (8/199) identified in our previous study (P =.008). We also fingerprinted a convenience sample of isolates from other laboratories in Denver; 13.6% (3/22) of these were false-positive, a rate similar to the 11.9% rate (5/42) identified for other laboratories in our previous study (P =.84).

CONCLUSIONS

Laboratory cross-contamination decreased significantly after relatively simple, inexpensive changes in laboratory policies and practices. Cross-contamination continued to occur in other laboratories in Denver.

Controlled clinical comparison of BACTEC plus anaerobic/F to standard anaerobic/F as the anaerobic companion bottle to plus aerobic/F medium for culturing blood from adults

To determine the optimal anaerobic companion bottle to pair with BACTEC Plus Aerobic/F medium for recovery of pathogenic microorganisms from adult patients with bacteremia and fungemia, we compared Plus Anaerobic/F bottles with Standard Anaerobic/F bottles, each of which was filled with 4 to 6 ml of blood. The two bottles were paired with a Plus Aerobic/F bottle filled with 8 to 12 ml of blood. A total of 14,011 blood culture sets were obtained. Of these, 11,583 sets were received with all three bottles filled adequately and 12,257 were received with both anaerobic bottles filled adequately. Of 818 clinically important isolates detected in one or both adequately filled anaerobic bottles, significantly more staphylococci (P < 0.001), streptococci (P < 0.005), Escherichia coli isolates (P < 0.02), Klebsiella pneumoniae isolates (P < 0.005), and all microorganisms combined (P < 0.001) were detected in Plus Anaerobic/F bottles. In contrast, significantly more anaerobic gram-negative bacilli were detected in Standard Anaerobic/F bottles (P < 0.05). Of 397 unimicrobial episodes of septicemia, 354 were detected with both pairs, 30 were detected with Plus Aerobic/F-Plus Anaerobic/F pairs only, and 13 were detected with Plus Aerobic/F-Standard Anaerobic/F pairs only (P < 0.05). Significantly more episodes of bacteremia caused by members of the family Enterobacteriaceae (P < 0.05) and aerobic and facultative gram-positive bacteria (P < 0.025) were detected with Plus Anaerobic/F bottles only. In a paired-bottle analysis, 810 of 950 isolates were recovered from both pairs, 90 were recovered from Plus Aerobic/F-Plus Anaerobic/F pairs only, and 50 were recovered from Plus Aerobic/F-Standard Anaerobic/F pairs only (P < 0.001). Paired Plus Aerobic/F-Plus Anaerobic/F bottles yielded significantly more staphylococci (P < 0.001), streptococci (P < 0.05), and members of the family Enterobacteriaceae (P <0.001). We conclude that Plus Anaerobic/F bottles detect more microorganisms and episodes of bacteremia and fungemia than Standard Anaerobic/F bottles as companion bottles to Plus Aerobic/F bottles in the BACTEC 9240 blood culture system.

Epidemiological and ecological characteristics of past dengue virus infection in Santa Clara, Peru

To determine risk factors associated with dengue (DEN) virus infection among residents of Santa Clara, Peru, a rural Amazonian village near Iquitos, a cross-sectional serological, epidemiological and environmental survey was conducted. Demographic, social and behavioural information was obtained by standardized questionnaire from 1225 Santa Clara residents (61.3%) aged 5 years or older. Additional data were obtained on the environmental variables and immature mosquito species and abundance surrounding each household (n = 248). Sera that had been collected previously by the Peruvian Ministry of Health from residents were tested by an enzyme-linked immunosorbent assay (ELISA) for DEN virus IgG antibody. Antibody identity was verified as DEN by plaque reduction neutralization test. Data on individuals were analysed by univariate and multivariable methods, and independent sample t-tests. Spatial clustering was evaluated by comparing distances among DEN positive households. Overall, antibody prevalence was 29.4 % and more than doubled from the youngest to the oldest age groups, but did not differ by sex. Curiously, length of residence in Santa Clara was negatively associated with DEN virus antibodies. More frequent travel to Iquitos was positively associated with seroprevalence. Residents who obtained water from a river source rather than a local well also had significantly higher antibody prevalence. None of the environmental variables measured at each household corresponded to the patterns of antibody distribution. Of the larval mosquitoes found around residences, all were determined to be species other than Aedes. No evidence of spatial autocorrelation among antibody-positive households was detected. These results strongly suggested that recent DEN virus transmission did not occur in the village and that most infections of residents of this rural village were acquired while visiting the city of Iquitos.

Effects of wortmannin upon the late stages of the secretory pathway of AtT-20 cells

Heterotrimeric GTP-binding (G) proteins, termed Ge, have a role in the late stages of the adrenocorticotrophin (ACTH) secretory pathway in the mouse AtT-20/D16-16 anterior pituitary tumour cell line. The wortmannin sensitivity of Ge-controlled mechanisms in AtT-20 cells was investigated to provide information on the possible mechanisms linking Ge with secretion. Permeabilised cells exposed to calcium ions (10(-9) to 10(-3) M), guanosine 5'-O-(3-thiotriphosphate) (GTP-gamma-S) (10(-8) to 10(-4) M) and mastoparan (10(-8) to 10(-5) M) demonstrated a significant and concentration-dependent stimulation of ACTH secretion from non-stimulated levels for all three agents. Coincubation with wortmannin (10(-5) M) significantly inhibited both calcium-independent and -stimulated secretion. The effect of wortmannin was concentration-dependent being maximal at 10(-6) M. The study shows that wortmannin inhibits both calcium-independent and -stimulated secretion from permeabilised AtT-20 cells indicating a role for phosphatidylinositol-3 kinase in determining the size of the readily releasable pool of ACTH and/or in mediating calcium/Ge-evoked secretion from this pool.

Comparison of iodophor and alcohol pledgets with the Medi-Flex blood culture prep kit II for preventing contamination of blood cultures

Iodophor and alcohol pledgets were compared with the Medi-Flex Prep Kit II for skin disinfection before venipuncture. Of 12,367 blood cultures collected, 6,362 were done with conventional pledgets and 6, 005 were done with Medi-Flex kits. Contamination occurred in 351 of 6,362 blood cultures (5.5%; range, 3.7 to 8.1%) with conventional pledgets versus 328 of 6,005 (5.5%; range, 3.5 to 7.5%) with Medi-Flex kits.

Treatment for clinical malaria is sought promptly during an epidemic in a highland region of Uganda

Early diagnosis of malaria followed by appropriate treatment can help reduce related morbidity and mortality as well as interrupt transmission. Previous studies of household responses to malaria have tended to focus on endemic areas where the burden of this disease is greatest. With the apparent increasing frequency of epidemics in African highlands, a better understanding of treatment behaviours in areas of unstable transmission may be important to future public health interventions. This study was undertaken following a serious epidemic of malaria in the highlands of south-western Uganda. Our objectives were to characterize actions taken by both adults and caretakers of children < or =5 years old during their most recent episode of self-diagnosed malaria, and to identify factors that were associated with prompt treatment at a health facility. A survey of 300 households selected in a 2-stage cluster sampling procedure produced 453 adult respondents and 133 caretakers of children < or =5 years old. We found that almost 65% of adults and 62% of children who had experienced an episode of malaria in the last year (most during the epidemic) had sought treatment from a health facility first as opposed to self-treatment. Most of these people had visited the health facility within 1 day of symptom onset. By the end of their malaria episode, over 87% of adults and 80% of children had visited a health facility at least once. Factors associated with prompt presentation at a health facility included severity of illness, household proximity to a health facility, and knowledge of malaria prevention methods. Our results indicate that there is an important role for the formal health care system in mitigating morbidity and mortality and reducing transmission during malaria epidemics in Uganda.

Modeling contact networks and infection transmission in geographic and social space using GERMS

BACKGROUND

Stochastic models of discrete individuals and deterministic models of continuous populations may give different answers to questions about infectious diseases.

GOAL

Discrete individual model formulations are sought that extend deterministic models of infection transmission systems so that both model forms contribute cooperatively to model-based decision making.

STUDY DESIGN

GERMS models are defined as stochastic processes in continuous time with parameters analogous to those in deterministic models. A GERMS model simulator was developed that insured that the rate of events depended only on the current state of model.

RESULTS

The confidence intervals of long-term averages of infection level in simulated GERMS models were shown to contain the deterministic model means.

CONCLUSION

GERMS models provide a convenient framework for testing the sensitivity of model-based decisions to a variety of unrealistic assumptions that are characteristic of differential equation models. GERMS especially facilitates making more realistic assumptions about contact patterns in geographic and social space.

Early warning of malaria epidemics in African highlands using Anopheles (Diptera: Culicidae) indoor resting density

Several highland regions of Africa recently have suffered malaria epidemics. Because malaria transmission is unstable and the population has little or no immunity, these highlands are prone to explosive outbreaks when densities of Anopheles exceed critical levels and conditions favor transmission. If an incipient epidemic can be detected early enough, control efforts may reduce morbidity, mortality, and transmission. Here we present three methods (direct, minimum sample size, and sequential sampling approaches) that could be used to determine whether the household indoor resting density of Anopheles gambiae s.I. has exceeded critical levels associated with epidemic transmission. Data on Anopheles density before, during, and after a malaria epidemic (December 1997-July 1998) in the highlands of southwestern Uganda were evaluated to demonstrate the application of these three approaches. During this epidemic, a density of 0.25 Anopheles mosquitoes per house was associated with epidemic transmission, whereas 0.05 mosquitoes per house was chosen as a normal level expected during nonepidemic months. The direct approach to calculating mean Anopheles density with an allowable error of 20-50% of the mean would require the sampling of 102-16 houses, respectively. In contrast, with only seven houses, the minimum sample size approach could be used to determine whether Anopheles density had exceeded the critical level. This method, however, would result in an overestimation of the risk of an epidemic at low Anopheles density. Finally, a sequential sampling plan could require as many as 50 houses to conclude that risk of an epidemic existed, but this disadvantage is offset by the ability to preset the probabilities of concluding that risk of an epidemic exists at both the critical and normal Anopheles densities. Our study illustrated that it is feasible, and probably expedient, to include monitoring of Anopheles density in highland malaria epidemic early warning systems.

Serious streptococcal infections produced by isolates resistant to streptogramins (quinupristin/dalfopristin): case reports from the SENTRY antimicrobial surveillance program

The emergence and sustained prevalence of Gram-positive organisms resistant to antimicrobials has been of interest for over a decade. Quinupristin/dalfopristin (formerly RP 59500 or Synercid) is a new injectable streptogramin combination that has been reported to have activity against Gram-positive organisms, even those with documented MLS(B) resistance. However, the two case reports presented here illustrate three well-documented Streptococcus spp. strains (S. mitis, S. pneumoniae) to be resistant to quinupristin/dalfopristin (MICs at 3, 8, and 12 microg/ml) following referral as routine isolates in the SENTRY Antimicrobial Surveillance Program. The S. pneumoniae pleural fluid isolate was cross-resistant to erythromycin. Both bacteremic S. mitis strains were resistant to macrolides (erythromycin, azithromycin, clarithromycin), lincosamides (clindamycin), and fluoroquinolones. Patient histories indicated no prior use of MLS class antimicrobials for the S. mitis case, but the patient having the S. pneumoniae isolate did receive prior treatment of erythromycin and clindamycin. All isolates had modestly increased penicillin MICs of 0.12 microg/ml. The mode of resistance to quinupristin/dalfopristin was not evident (sat A-negative by PCR); and these cases illustrate the existence of streptogramin-resistant isolates before the introduction of this antimicrobial class into human clinical practice.

Land use change alters malaria transmission parameters by modifying temperature in a highland area of Uganda

As highland regions of Africa historically have been considered free of malaria, recent epidemics in these areas have raised concerns that high elevation malaria transmission may be increasing. Hypotheses about the reasons for this include changes in climate, land use and demographic patterns. We investigated the effect of land use change on malaria transmission in the south-western highlands of Uganda. From December 1997 to July 1998, we compared mosquito density, biting rates, sporozoite rates and entomological inoculation rates between 8 villages located along natural papyrus swamps and 8 villages located along swamps that have been drained and cultivated. Since vegetation changes affect evapotranspiration patterns and, thus, local climate, we also investigated differences in temperature, humidity and saturation deficit between natural and cultivated swamps. We found that on average all malaria indices were higher near cultivated swamps, although differences between cultivated and natural swamps were not statistically significant. However, maximum and minimum temperature were significantly higher in communities bordering cultivated swamps. In multivariate analysis using a generalized estimating equation approach to Poisson regression, the average minimum temperature of a village was significantly associated with the number of Anopheles gambiae s.l. per house after adjustment for potential confounding variables. It appears that replacement of natural swamp vegetation with agricultural crops has led to increased temperatures, which may be responsible for elevated malaria transmission risk in cultivated areas.

Coccidioidomycosis meningitis with massive dural and cerebral venous thrombosis and tissue arthroconidia

To our knowledge we report the first case of meningitis from Coccidioides immitis associated with massive dural and cerebral venous thrombosis and with mycelial forms of the organism in brain tissue. The patient was a 43-year-old man with late-stage acquired immunodeficiency syndrome (AIDS) whose premortem and postmortem cultures confirmed C immitis as the only central nervous system pathogenic organism. Death was attributable to multiple hemorrhagic venous infarctions with cerebral edema and herniation. Although phlebitis has been noted parenthetically to occur in C immitis meningitis in the past, it has been overshadowed by the arteritic complications of the disease. This patient's severe C immitis ventriculitis with adjacent venulitis appeared to be the cause of the widespread venous thrombosis. AIDS-related coagulation defects may have contributed to his thrombotic tendency.

Surgical interruption of pelvic nerve pathways for primary and secondary dysmenorrhoea

BACKGROUND

Dysmenorrhoea is the occurrence of painful menstrual cramps of uterine origin and is a very common gynaecological complaint. Medical therapy for dysmenorrhoea includes oral contraceptive pills (OCP) and nonsteroidal anti-inflammatory drugs (NSAIDS) which both act by suppressing prostaglandin levels. While these treatments are very successful there is still a 20-25% failure rate and surgery has been an option for cases of dysmenorrhoea that fail to respond to medical therapy. Uterine nerve ablation (UNA) and presacral neurectomy (PSN) are two surgical treatments that have become increasingly utilised in recent years. These procedures both interrupt the majority of the cervical sensory nerve fibres, thus diminishing uterine pain. Uncontrolled studies have supported the use of these procedures for primary dysmenorrhoea however both operations only partially interrupt some of the cervical sensory nerve fibres in the pelvic area; therefore dysmenorrhoea associated with additional pelvic pathology may not always benefit from this type of surgery.

OBJECTIVES

To assess the effectiveness of surgical interruption of pelvic nerve pathways as treatment for primary and secondary dysmenorrhoea, and to determine the most effective surgical treatment.

SEARCH STRATEGY

Electronic searches of the Cochrane Menstrual Disorders and Subfertility Group Register of controlled trials, MEDLINE, and EMBASE were performed to identify relevant randomised controlled trials (RCTs). Attempts were also made to identify trials from citation lists of review articles and handsearching. In most cases, the first or corresponding author of each included trial was contacted for additional information.

SELECTION CRITERIA

The inclusion criteria were randomised comparisons of surgical techniques of interruption of the pelvic nerve pathways (both open and laparoscopic procedures) for the treatment of primary and secondary dysmenorrhoea. The main outcome measures were pain relief and adverse effects.

DATA COLLECTION AND ANALYSIS

Seven RCTs were identified that fulfilled the inclusion criteria for this review. One trial (Sutton 1994) was excluded because another treatment was given in combination with destruction of pelvic nerve pathways and the effects of these two treatments could not be separated. Of the remaining six trials, three were included in the meta-analysis (Chen 1996, Candiani 1992, Lichten 1987). The results of the other three trials (Dover 1999, Tjaden 1990, Vercellini 1997) were included in the text of the review for discussion because the data were not available in a form that allowed them to be combined in a meta-analysis.

MAIN RESULTS

For the treatment of primary dysmenorrhoea there is some evidence of the effectiveness of uterine nerve ablation (UNA) when compared to a control of no treatment. The comparison between UNA with presacral neurectomy (PSN) for primary dysmenorrhoea showed no significant difference in pain relief in the short term, however long term PSN was shown to be significantly more effective. For the treatment of secondary dysmenorrhoea the identified RCTs addressed only endometriosis. The treatment of UNA combined with surgical treatment of endometrial implants versus surgical treatment of endometriosis alone showed that the addition of UNA did not aid pain relief. For PSN combined with endometriosis treatment versus endometriosis treatment alone there was also no overall difference in pain relief, although the data suggests a significant difference in relief of midline abdominal pain. Adverse events were significantly more common for presacral neurectomy, however the majority were complications such as constipation, which may spontaneously improve.

REVIEWER'S CONCLUSIONS

There is insufficient evidence to recommend the use of nerve interruption in the management of dysmenorrhoea, regardless of cause. Future RCTs should be undertaken.

Highland malaria in Uganda: prospective analysis of an epidemic associated with El Niño

Malaria epidemics in African highlands cause serious morbidity and mortality and are being reported more frequently. Weather is likely to play an important role in initiating epidemics but limited analysis of the association between weather conditions and epidemic transmission parameters has been undertaken. We measured entomological variables before and during an epidemic of malaria (which began in February 1998) in a highland region of south-western Uganda and analysed temporal variation in weather data against malaria incidence (estimated from clinic records), mosquito density and entomological inoculation rates (EIR). Indoor resting density of Anopheles gambiae s.l. was positively correlated with malaria incidence (r = 0.68, P < 0.05) despite extremely low vector densities. EIR totalled only 0.41 infectious bites per person during the entire 8-month study period. Rainfall during and following the El Niño event in 1997 was much higher than normal, and rainfall anomaly (difference from the mean) was positively correlated with vector density 1 month later (r = 0.55, P < 0.05). Heavier than normal rainfall associated with El Niño may have initiated the epidemic; the relationship between temperature and transmission parameters remains to be defined. The results from this study indicate that, in this highland population, epidemic malaria may occur at extremely low inoculation rates.

Epidemiology of hookworm infection in Itagua, Paraguay: a cross sectional study

A cross-sectional study in Itagua, Paraguay tested 192 people for the presence, intensity and species of hookworm infection. Fifty-nine percent of these individuals were found to be infected. Intensity of infection was determined on 92% of infected individuals by quantitative egg counts. The high intensity hookworm infections, which cause the greatest morbidity, were clustered between the ages of five and 14 years. No differences were seen between genders. The species of hookworm was determined for parasites reared from 72% of infected individuals. Both Necator americanus and Ancylostoma duodenale were identified, although the former species predominated. We conclude that hookworm infection continues to be a public health problem in Paraguay, particularly among children and adolescents who suffer from high intensity infections. A. duodenale continues to persist in the Western Hemisphere and has not been completely displaced by N. americanus.

Controlled clinical comparison of bioMérieux VITAL and BACTEC NR-660 blood culture systems for detection of bacteremia and fungemia in adults

A total of 9,446 blood cultures were collected from adult patients at three university-affiliated hospitals. Of these, 8,943 cultures were received with both aerobic bottles filled adequately; 885 yielded 1,016 microorganisms, including 622 isolates (61%) that were the cause of sepsis, 337 isolates (33%) that were contaminants, and 57 isolates (6%) that were indeterminate as the cause of sepsis. With the exception of Staphylococcus aureus, which was recovered more often from VITAL aerobic bottles, more pathogenic microorganisms were recovered from BACTEC NR6 (aerobic) bottles than from VITAL aerobic bottles. Growth of pathogenic microorganisms was detected earlier in VITAL aerobic bottles. A total of 8,647 blood cultures were received with both anaerobic bottles filled adequately; 655 yielded 740 microorganisms, including 486 isolates (66%) that were the cause of sepsis, 215 isolates (29%) that were contaminants, and 39 isolates (6%) that were indeterminate as the cause of sepsis. More pathogenic microorganisms were recovered from VITAL anaerobic bottles than from BACTEC NR7 (anaerobic) bottles. Growth of pathogenic microorganisms was detected earlier in VITAL anaerobic bottles. In 8,500 sets all four bottles were received adequately filled. When paired aerobic and anaerobic bottle sets (systems) were compared, more pathogenic microorganisms (again with the exception of S. aureus) were recovered from the BACTEC system. For the 304 septic episodes (253 unimicrobial and 51 polymicrobial), significantly more were detected by the BACTEC system. We conclude that VITAL requires modification to improve recovery of pathogenic microorganisms to make it competitive with other commercially available blood culture systems.

Sandflies (Diptera: Psychodidae) associated with epidemic cutaneous leishmaniasis in Sanliurfa, Turkey

As part of a project to study the possible impact of environmental change on health in southeastern Turkey, we evaluated sandfly species diversity, abundance, and habitat associations in an urban area where cutaneous leishmaniasis was undergoing epidemic re-emergence. Houses and caves in and around the city of Sanliurfa, Turkey, were sampled using mechanical aspirators, sticky papers, and CDC light traps. Of 1,649 sandflies captured, including 6 Phlebotomus and 1 Sergentomyia species, nearly all were P. papatasi (Scopoli) (967) or P. sergenti Parrot (674). Sandflies were active during June-September (hot dry season), but not during January (cool rainy season). Resting phlebotomines were abundant inside houses. Houses sampled in 3 neighborhoods with a high cutaneous leishmaniasis incidence (9-65 cases per 1,000 population) had > 10 times more flies than at a comparison site where few cases (0.2 per 1,000) have been reported. Results indicated that P. sergenti or P. papatasi were the probable vectors of cutaneous leishmaniasis during this outbreak and that control of these sandflies may eliminate transmission.

Biological and clinical responses of west African sheep to Crimean-Congo haemorrhagic fever virus experimental infection

West African sheep appear to play a central role as virus hosts in the maintenance cycle of Crimean-Congo haemorrhagic fever (CCHF) virus in endemic areas and also because of their role as a principal host of the CCHF virus tick vector. In an effort to clarify CCHF epidemiological significance in sheep, we studied the biological and clinical aspects of sheep experimentally infected with CCHF virus. West African sheep breeds were infected either by intraperitoneal inoculation or by infestation with experimentally CCHF-virus-infected ticks (Hyalomma truncatum). A total of 17 sheep including controls as well as 5 lambs from their progeny were monitored. A moderate but constant fever was observed (39.7 degrees C +/- 0.3) which correlates with the viraemia. Virus was reisolated from blood samples taken from day 3 to day 9 postinfection (p.i.) at a mean titre of 3.3 log LD50/ml. The virus was detected for a period of time of 7 days in non-immune sheep and for less than 4 days in previously immunized sheep. In non-immune sheep, antibody detected by ELISA showed an IgM response on day 7 p.i., followed by an IgG response one day later. Five infected sheep, surveyed for liver and kidney biological markers, showed hepatic dysfunction with a moderate serum aspartate transferase rise to 210 U/l. Out of four sheep tested for blood markers, two showed an abnormal blood cell count, with marked neutrophilia of up to 63% lasting for two weeks. Infected pregnant ewes produced antibodies in their milk at a significant titre (1:1,000), and antibodies were recovered in the sera of nursing lambs from their first meal to 50 days after birth. These findings are discussed; they demonstrate that, in spite of a high turnover of local sheep herds (median age of 3 years) and long-term CCHF antibody persistence (> 3 years), sheep can be infected and efficiently transmit the virus at least once in a lifetime.

Epidemiology of endemic Oropouche virus transmission in upper Amazonian Peru

A cross-sectional serosurvey of a rural community near Iquitos, Peru was conducted to determine Oropouche (ORO) virus antibody prevalence and risk factors for human infection. Venous blood samples, and demographic, social, and risk factor data were obtained from people age five years of age and older who lived in the village of Santa Clara on the Nanay River, a tributary of the Amazon River. Sera were tested for ORO viral antibody by an ELISA. The specificity of viral antibody reactivity was determined by a standard plaque-reduction neutralization test. Interview data were analyzed by univariate and multiple logistic regression to determine which variables were statistically associated with previous ORO viral infection, as indicated by the presence of IgG antibody. Final models were evaluated based on log-likelihood and Wald chi-square. Clustering of seropositive residents within houses was analyzed by the method of Walter. Among 1,227 persons sampled, 33.7% (n=414) were positive for ORO viral IgG antibody. Overall, antibody prevalence was similar for males (33.9%) and females (33.6%), and increased significantly with age for both sexes to include more than half of persons more than 25 years of age. The length of residence in the village was positively associated with serologic status; persons who had moved to the village within the past 15 years were less likely to be seropositive than life-long residents of the same age. Antibody prevalence among immigrants who had lived in Santa Clara more than 15 years was similar to that in life-long residents. The activity most predictive of previous ORO viral infection was travel to forest communities and travel to Iquitos. No evidence of spatial heterogeneity in ORO virus antibody distribution was observed. Results suggested that endemic transmission of ORO virus in this region has been ongoing during many decades, and that people are at considerable risk of infection.